Automatic air valve for sand traps



R. A. LIGHT ET AL 1,840,964

Jan. 12, 1932.

AUTOMATIC AIR VALVE FOR SAND TRAPS Filed April 11, 1931 v 1 F ///////Mum M a lNVfA/TORS 152% W. Price, 5 v

Patented Jan. 12, 1932 UNITED STATES PATENT OFFICE ALPII A. LIGHT, orCYNWYD, AND JOSEPH w. PRICE, JR, or PH ILADELPHIA, PEN

- sYLvANIA, ASSIGNORS TO THE. UNITED STATES METALLIC PACKING COMPANY, orIIHILALDELPHIA, PENNSYLVANIA, A CORPORATION or PENNSYLVANIA I AUTOMATICAIR VALVE FOB. SAND rms Application filed April 11', 1931, Serial No.529,462, and in Canada May 21, 1931.

Our invention relates to sandingmechanism such as isused in connectionwith locomotives and is intended for use in connection with sand trapsprovided with air nozzles, one

1; directed into the trap and operating to 'de-' liver'sand from thetrap into the delivery pipe and the other directed into the deliverypipe-and operating to expel a blast of'air 'which will clean thedelivery pipe'of ob- 1O structions whichma-y have accumulated in it.

The object of our invention is to provide an automatic air control valveoperable by the admission of pressure air from the supply pipe of thesystem and operating in normal ltposition, that. is, when no'pressureair'is fiowin'g to-thetrap, to cut off all communication betweenrthe airsupply pipe and the pipes leading from the-valve to the delivery andcleaner nozzles of the trap, and operating when air is admitted to thevalve to first conmeet the airsupply pipe with an outlet passage leadingto the cleaner nozzle,- then to close thisconnection and open theconnection between the inlet pipe and the outlet port 25 leading to thesand deliverynozzle.

The purposeof this invention is to secure very shortly after theadmissionof air to the valve a short blast of full pressure air throughthe cleaner nozzle followed by a continuous delivery'of air to'thedeliverynozzle and also 1 when the supply of air under pressureis cutoff to close the connection between the nozzles .of the trap andthevalve chamber. Further objects and features of ou r invention will be 35explained in connection with the drawings, which illustrate a preferredconstruction of our automatic air delivery valve and is intended for usein connection with a sander system such as is shown for instancein ourapplication, Serial No. 460,854, filed June 13, l930.' 1 I Y "In thedrawings, 7 I;

Figure l'is atop view of our automatic filve.

Figure 2 is a section on the line 2-2 of Fig. l, and 7 Figure-.3isawsecti Fig.',,;1. 4 =A isra cylindrical-chamber, closed at both in onthe I line of 9 ends-by heads indicated-at B and Ganddivided by amovable wall, shown as a piston head G into a valve chamber A and aseparate air containing chamber indicated at A Into the valve chamber Aleads an admission port indicated at D, which is connected with theusual air supply pipe for air under pressure, indicated at D This port.D is shown as longitudinally elongated where it passes through the innerwall of the cylinder, as indicated at D so as to maintain registry withthe air groove of the cylindrical valve working in the cylinder and tobe de' scribed. Provision for the delivery of air from this chamber ismade by ports indicated at F, F located on opposite sides of the cylinsdrical valve casing and radially disposed with regard to the portleading to the sand delivery nozzles at angles of 90 thereto. Theseports F, F are connectible to the cleaner nozzles of a pair of sandtraps and the construction s and disposition ofthese ports in connectionwith ports connectible with the delivery nozs zles of the traps is suchas to provide for a convenient arrangement of the pipes leading to thetraps. 75

At a difi'erent, and, as shown, a lower level there is formed throughthe wall of the valve chamber an outlet port indicated at E, which, asshown, and where, as is usually the case, the valve is to be connectedto a pair of sand traps, is preferably made of a single port formedthrough the inner wall of the valve casing cylinder, said portconnecting with bifurcated passages indicated at E E to which separateair pipes can be attached a; leading to the sand delivery nozzles of twotraps. 'G is a piston valve fitting in the cylindrical valve casing Aand having as shown a head G which forms a movable wall for the aircontaining chamber A separating it from the valve chamber A The body ofthe piston valve is circumferentia lly grooved as indicated at G saidgroove being so located and shaped that it willremain in registry withthe air inlet portD in all positions of the valve, that it will be outof registry with all of the air delivery ports when the valve is innormally retracted position and that as the valve is actuated it willfirst register with and then pass out of registry with the air deliveryports F and F thus opening these ports for a brief period and will thenregister with and'remain in registry with the port E so that in thefinal position'assnrned by the moving valve this port will remaincontinuously open. An air passage, preferably of restricted area, mustbeprovided to deliver air to theair containingchamber A whenair isadmitted to the inlet port and such apassage may conven-' iently be madethrough the piston valve between the groove G and the chamber-A--.- Sucha passage is indicated at H. I indicates a spring seated on the' lowerhead of the casing and pressing against; the lower end of thepistonvalve." f

The normal inoperative position of the valve is that indicated in" thedrawings, the valve being held in this position by the" spring I and'thevalve in this position while per: mitting the entrance of air to thegroove Gr v closes all ofthe outlet ports in the valve cha1nber A Whenpressure air is admitted through theinletport'D it passes freely intothe groove-G 'in the valve and passes thence through the restricted airpassage I-I tothe chamber-A building up pressure in this chamber, which,acting on the piston head G will,whenit'attains sufficient pressure,overcome the pressure of thespring I, holding the valve in non-operativeposition and move the piston valve snowman so as, to bring the'groovl'iGfirst into registry with the cleaner' ports F and F delivering a fullhead of pressure air through these ports for'a brief interval, thefurther downward movement of the valveclosing these ports bringingitsgroove into 'registrywith the "delivery port E, so that thereafterall of the air passing through the valve is delivered to the sanddelivery nozzles. IV hen the supply of air under pressure'isfcut off theair in the chamber A? will escape through the passage H and thereleaseoi pressure on the movable Wall piston will then permit thespring I to restore the valve to normal inoperative position. w 7

It will be seen that by the use ofour valve weprovide for the deliveryof all the air coming from the high pressure supply pipe to the outletports leading to the cleaner nozzles at high pressure for ai briefinterval of time and then forthe cutting off of air tothesecleaneriports and the delivery of all the air thereafterthrough theports connectedto' the sand delivery nozzles. It will also beobviousthat by our construction the valve in normal inoperative positioncloses" all r con nection with the outletjports and thus pre- P g ofany; particles of sand or dust into the valvecasingi 7Anotheradvantageous feature of our con struction is that if the valve onadmission of air does n tfor any reason operate no air,

will be lost, as both outlet ports will remain closed.

Having now described our invention, what We claim as new andv desire tosecure by Letters'Patent, is-:

'1, An automatic air distributing valve adapted to be located in the airpipe system leading from a source of air under pressure tofa sand traphaving air delivery nozzles,

ible respectively with the cleaner and deliv- V ery nozzles of a sandtrap, valve mechanism located in said casing normally closing allconnection between the inlet and outlet ports and shiftable in thecasing to progressively open and close the cleaner port and'then to openthe delivery port, resilient means opcrating to normallyhold the valvemechanism in position to-close the delivery ports and aconnectionbetween the valve mecha nism' and the movable wall of the airzc'hambe'rwhereby when'pressure airis admitted to said "chamber the valve isp'rogressively shifted to progressively open and close" the cleaner port"and then to open tl1e sand delivery ports." I V, I 1 V 2; In anautomatic air controlled valve as called forin claim 1,'the constructionof the'valve mechanism as apiston valve work ing in the valve casingchamber andgrooved to maintain'communication with" the inlet port in allpositions of the valve, said groove being so formed that on'the movementof the piston-valve it communicates for a portion of the movement of thevalve with the'outlet port leading'to the cleaner nozzle and then withthe outlet port leading to the sand delivery nozzle. a

3. In an automatic air control valve as called for in claim 1, a pistonvalve having a cylindrical head which forms the movable wall of the airchamber and the cylindrical body fitting in the valve casing, saidc'ylindrical valve being formed With a groove so shaped as to maintaincommunicationwith the inlet-port in all-"positions of the valve, and asthe valve is moved to progressively open and close the air port leadingto; the cleaner nozzle of the trap and then toopen the air port leadingto the sand delivery nozvbody fitting in the valve casing, said cylindrical valve being formed with a groove so shaped as to maintaincommunication with the inlet port in all positions of the valve leadingfrom a source of air under pressure to a sand trap having air deliverynozzles, one leading into the;trap to effect the delivcry of sandtherefrom and the other directed into the'delivery pipe leading from thesand trap, said valve comprisin in combination a cylindrical casing divied into an air chamber and a valve chamber by a movable wall, said valvechamber having an inlet port leading into it, two outlet ports adaptedto' be connected to the cleaner nozzles of two traps'and located onopposite sides of the valve casing, a bifurcated outlet port connectiblewith delivery nozzles of two traps and located at a point in the valvecasing approximately midway between the outlet ports before mentioned, apiston valve working in the cylindrical casing provided with a groove soformed as to maintain communication with the inlet port in all positionsof the valve, to close'all outlet ports when the valve is in normalinoperative position, to progressively open and close the outlet portsconnectible with the cleaning nozzles as the valve moves from normalposition and then to open the bifurcated outlet port connectible withthe distributing nozzles, a movable wall separating the air transmittingand air containing chambers operatively connected with thepiston valve,an air conduit whereby air is admitted to the air chamber when pressureair is delivered a to the admission port of the valve casing and meansoperating to restore the valve and movable wall to normal inoperativeposition when pressure fluid is cut ofi from the valve casing. o RALPHA. LIGHT.

JOSEPH W. PRICE, JR.

